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<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <script>
      // 形（形式）参（参数）
      function fn(a, b, ...c) {
        console.log(fn.name, fn.length);
      }
      const user = {
        sayBye: function (x, y, z) {
          console.log(this.sayBye.name, this.sayBye.length);
        }, // sayBye:{}
      };
      const arr = [
        function (i, j, k, h) {
          console.log(this[0].name, this[0].length);
        },
      ];
      fn(1, 2, 3, 4); //实际参数
      user.sayBye();
      arr[0]();
    </script>
  </body>
</html>
